At my local pet store there is a thing that you can buy that slides right over the intake. I don't know what it is called, but I had to cut mine to size. It's the black thing. It isn't the most gorgeous thing, and I like to put a plant in front of mine, but my fish never really bug it anyways.

Like Hadoken said, it could be because of plastic decorations
But the reason for it or why he's not healing could easily be that you arent doing enough water changes. In a 1 gallon you should at minimum be doing 2 100% changes per week.
For treatment I'd scrap the bettafix *for future referance never treat a betta with any medication with "fix" at the end, it can damage their labrynth organ* and instead use AQ salt at 1tsp/gallon for 10 days doing a 100% change each day.

Getting a heater would probably be a really good idea too to keep your temperature stable

Edit::: That sponge thing is called a prefilter sponge -- Fluval has theirs for sale at petsmart for like $2. Kind of hard to find so you should ask a store employee where they would be if you cant find them right away. When I bought mine they were under the gravel vacuums.

It almost looks like a sponge. Thank you I will go look. When I first put bubba in the tank he was being curious than started to play by it which I think started the tearing in the first place

Bettas are naturally curious. You can use this curiosity to teach them all kinds of tricks. I recently taught mine to "kiss" the tip of a finger. Really it's nipping, but it's fish lips so whatever. LOL.

Also, everyone else it right. 1G tanks can house a happy betta, but they HAVE to be EXTREMELY well taken care of. As in everything that aemaki stated. (:

The employees at the petsmart by me aren't very helpful I asked about sponges to baffle the filter and they could only find one type of sponge than they sent me to bettafix. Sorry for so many questions I don't know to much about bettas.